macos_pick_files

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: the tool opens a dialog, allows multiple selection, and returns paths or null on cancellation. However, it lacks details on permissions needed, UI behavior (e.g., modal vs. non-modal), error handling, or platform-specific constraints, which are important for a system-level tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core purpose in the first clause and efficiently covers key behaviors in two sentences. Every sentence earns its place by providing essential information without redundancy, making it highly concise and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (3 parameters, no output schema, no annotations), the description is mostly complete: it explains what the tool does, its selection behavior, and return values. However, it could improve by mentioning platform-specific details (macOS-only) or interaction with other tools, but it adequately covers the basics for an agent to use it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all parameters (prompt, defaultLocation, fileTypes). The description does not add any parameter-specific semantics beyond what the schema provides, such as examples or usage tips. Baseline 3 is appropriate as the schema handles the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose with specific verbs ('Open a file picker dialog allowing multiple selection') and resource ('array of paths'), distinguishing it from siblings like 'macos_pick_file' (singular) and 'macos_pick_folder' (folders). It explicitly mentions the return behavior, which is crucial for understanding its function.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context by stating it 'allows multiple selection' and returns 'null if cancelled,' which helps differentiate from 'macos_pick_file' (likely single selection) and 'macos_save_dialog' (for saving). However, it does not explicitly state when to use this tool versus alternatives like 'macos_get_finder_selection' or provide exclusions, leaving some ambiguity.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.